A Review on Characterization of Sheep Wool Impurities and Existing Techniques of Cleaning: Industrial and Environmental Challenges

There is increasing concern regarding the methods for sheep wool processing currently used in the textile industry owing to the enormous volume of toxic effluents generated. A large portion of these effluents comprises toxic volatile organic compounds necessary for the water-based cleaning of sheep wool. Various methods have been proposed for wool fiber cleaning: carbonization, solvent bleaching, and ultrasound, traditional washing using various detergents in steam or hot water, and electrical discharge cleaning, and there are several methods to remove impurities (suint, wool grease, and vegetable matter). However, these methods raise concerns because they adversely affect the mechanical and chemical properties of wool fiber and consume large quantities of chemicals and freshwater. Environmental conservation is a key element influencing accelerated industrial growth. Environmental awareness has prompted extensive research in the field of wool cleaning to identify environment-friendly solutions that involve low energy consumption, eco-friendly chemicals, and reduced waste and emissions. Eco-friendly methods should be developed to replace the traditional washing methods used to clean sheep wool fibers.